Filter mask



FIG. 1 is a perspective view of a filter mask showing my new design;

FIG. 2 is a side elevational view thereof, the other side being a mirror image;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a rear elevational view thereof.

The strap in FIGS. 2 through 6 is shown broken away for convenience of illustration. 

The ornamental design for a filter mask, as shown and described. 